Medical probe device with optical viewing capability

ABSTRACT

A medical probe device comprising a catheter having a stylet guide housing with at least one stylet port in a side thereof and stylet guide means for directing a flexible stylet outward through at least one stylet port and through intervening tissue to targeted tissues. The stylet guide housing has an optical viewing means positioned for viewing the stylet and adjacent structure which includes a fiber optic channel means for receiving a fiber optic viewing device. The fiber optic channel means can include a guide port means for directing longitudinal movement of a fiber optic device with respect to the stylet guide means in a viewing zone and a flushing liquid channel in the stylet guide housing having an exit port positioned to direct flushing liquid issuing therefrom across the end of a fiber optic device when positioned in the viewing zone. The optical viewing means can comprise a viewing window positioned in the stylet guide housing for viewing the stylet when it is directed outward from its respective stylet port. The optical viewing means can include a fiber optic channel in the stylet guide housing for receiving the a fiber optic viewing device and aligning the viewing end thereof with the viewing window. Windowed devices can include a flushing liquid channel in the stylet guide housing having an exit port positioned to direct flushing liquid issuing therefrom across a surface of the viewing window.

RELATIONSHIP TO COPENDING APPLICATION

This application is a continuation of U.S. application Ser. No.08/062,364, filed May 13, 1993, now U.S. Pat. No. 5,435,805 which is acontinuation-in-part of application Ser. No. 07/929,638 filed Aug. 12,1992 and now abandoned; and a continuation in part of Ser. No.08/012,370 filed Feb. 2, 1993, and now U.S. Pat. No. 5,370,675. Theentire contents of the above applications are hereby incorporated byreference.

FIELD OF THE INVENTION

This invention is directed to a unique device and method for penetratingbody tissues for medical purposes such as tissue ablation and fluidsubstance delivery, for example. The device penetrates tissue to theprecise target selected in order to deliver energy to the tissue and/ordeliver substances. It limits this treatment to the precise preselectedsite, thereby minimizing trauma to normal surrounding tissue andachieving a greater medical benefit. This device is a catheter-likedevice for positioning a treatment assembly in the area or organselected for medical treatment with one or more stylets in the catheter,mounted for extension from a stylet port in the side of the catheterthrough surrounding tissue to the tissue targeted for medicalintervention.

In particular, this invention is directed to a medical probe deviceprovided with an optical viewing capability for precise positioning ofthe treatment device.

BACKGROUND OF THE INVENTION

Treatment of cellular tissues usually requires direct contact of targettissue with a medical instrument, usually by surgical proceduresexposing both the target and intervening tissue to substantial trauma.Often, precise placement of a treatment probe is difficult because ofthe location of targeted tissues in the body or the proximity of thetarget tissue to easily damaged, critical body organs, nerves, or othercomponents.

Benign prostatic hypertrophy or hyperplasia (BPH), for example, is oneof the most common medical problems experienced by men over 50 yearsold. Urinary tract obstruction due to prostatic hyperplasia has beenrecognized since the earliest days of medicine. Hyperplastic enlargementof the prostate gland often leads to compression of the urethra,resulting in obstruction of the urinary tract and the subsequentdevelopment of symptoms including frequent urination, decrease inurinary flow, nocturia, pain, discomfort, and dribbling. The associationof BPH with aging has been shown by the incidence of BPH in 50 percentof men over 50 years of age and increases in incidence to over 75percent in men over 80 years of age. Symptoms of urinary obstructionoccur most frequently between the ages of 65 and 70 when approximately65 percent of men in this age group have prostatic enlargement.

Currently there is no nonsurgical method for treating BPH which hasproven to be effective. In addition, the surgical procedures availableare not totally satisfactory. Currently, patients suffering from theobstructive symptoms of this disease are provided with few options:continue to cope with the symptoms (i.e., conservative management),submit to drug therapy at early stages, or submit to surgicalintervention. More than 430,000 patients per year in the United Statesundergo surgery for removal of prostatic tissue. These represent lessthan five percent of men exhibiting clinical significant symptoms.

Those suffering from BPH are often elderly men, many with additionalhealth problems which increase the risk of surgical procedures. Surgicalprocedures for the removal of prostatic tissue are associated with anumber of hazards including anesthesia related morbidity, hemorrhage,coagulopathies, pulmonary emboli and electrolyte imbalances. Theseprocedures performed currently can also lead to cardiac complications,bladder perforation, incontinence, infection, urethral or bladder neckstricture, retention of prostatic chips, retrograde ejaculation, andinfertility. Due to the extensive invasive nature of the currenttreatment options for obstructive uropathy, the majority of patientsdelay definitive treatment of their condition. This circumstance canlead to serious damage to structures secondary to the obstructive lesionin the prostate (bladder hypertrophy, hydronephrosis, dilation of thekidney pelves, chronic infection, dilation of ureters, etc.), which isnot without significant consequences. Also, a significant number ofpatients with symptoms sufficiently severe to warrant surgicalintervention are therefore poor operative risks and are poor candidatesfor prostatectomy. In addition, younger men suffering from BPH who donot desire to risk complications such as infertility are often forced toavoid surgical intervention. Thus the need, importance and value ofimproved surgical and non-surgical methods for treating BPH isunquestionable.

High-frequency currents are used in electrocautery procedures forcutting human tissue, especially when a bloodless incision is desired orwhen the operating site is not accessible with a normal scalpel butpresents an access for a thin instrument through natural body openingssuch as the esophagus, intestines or urethra. Examples include theremoval of prostatic adenomas, bladder tumors or intestinal polyps. Insuch cases, the high-frequency current is fed by a surgical probe intothe tissue to be cut. The resulting dissipated heat causes boiling andvaporization of the cell fluid at this point, whereupon the cell wallsrupture, and the tissue is separated.

Ablation of cellular tissues in situ has been used in the treatment ofmany diseases and medical conditions alone or as an adjunct to surgicalremoval procedures. It is often less traumatic than surgical proceduresand may be the only alternative where other procedures are unsafe.Ablative treatment devices have the advantage of using anelectromagnetic energy which is rapidly dissipated and reduced to anon-destructive level by conduction and convection forces of circulatingfluids and other natural body processes.

Microwave, radiofrequency, acoustical (ultrasound) and light energy(laser) devices, and tissue destructive substances have been used todestroy malignant, benign and other types of cells and tissues from awide variety of anatomic sites and organs. Tissues treated includeisolated carcinoma masses in organs such as the prostate, and glandularand stromal nodules characteristic of benign prostate hyperplasia. Thesedevices typically include a catheter or cannula which is used to carry aradiofrequency electrode or microwave antenna through a duct to the zoneof treatment and apply energy diffusely through the duct wall into thesurrounding tissue in all directions. Severe trauma is often sustainedby the duct wall during this cellular ablation process, and some devicescombine cooling systems with microwave antennas to reduce trauma to theductal wall. For treating the prostate with these devices, for example,heat energy is delivered through the walls of the urethra into thesurrounding prostate cells in an effort to ablate the tissue causing theconstriction of the urethra. Light energy, typically from a laser, isdelivered to prostate tissue target sites by "burning through" the wallof the urethra. Healthy cells of the duct wall and healthy tissuebetween the nodules and duct wall are also indiscriminately destroyed inthe process and can cause unnecessary loss of some prostate function.Furthermore, the added cooling function of some microwave devicescomplicates the apparatus and requires that the device be sufficientlylarge to accommodate this cooling system.

Application of liquids to specific tissues for medical purposes islimited by the ability to obtain delivery without traumatizingintervening tissue and to effect a delivery limited to the specifictarget tissue. Localized chemotherapy, drug infusions, collageninjections, or injections of agents which are then activated by light,heat or chemicals would be greatly facilitated by a device which couldconveniently and precisely place a fluid supply catheter opening at thespecific target tissue.

In addition to ultrasound positioning capabilities, it is desirable toprovide the operator with the ability to optically examine the locationand surfaces of the duct or other passageway in which the catheter ispositioned for treatment, to locate abnormalities and more importantly,to precisely position the catheter tip. Retention of fertility after BPHtreatment, for example, requires that the seminal vesical openings intothe urethra remain undamaged. Precise location of these openings and thepositioning of the catheter tip to avoid damage to them requiressimultaneous optical viewing of the urethra surface and the cathetertip.

OBJECTS AND SUMMARY OF THE INVENTION

It is one object of this invention to provide a device with an opticalviewing capability for penetrating tissue, through intervening tissuesto the precise target tissue selected for a medical action such astissue ablation and/or substance delivery, limiting this activity to theprecise preselected site, thereby minimizing the trauma and achieving agreater medical benefit.

Another object of this invention is to provide a device with opticalviewing capability for precise placement of the device which deliversthe therapeutic energy into targeted tissues while minimizing effects onits surrounding tissue.

A still further object of this invention is to provide a device andmethod for introducing fluid treatment agents such as flowable liquidsor gases, with greater precision and ease to a specific location in thebody.

A further object of this invention is to provide a thermal ablationdevice which provides more control over the physical placement of thestylet and over the parameters of the tissue ablation process.

In summary, the device of this invention is a medical probe devicecomprising a catheter having a stylet guide housing with at least onestylet port in a side thereof and stylet guide means for directing aflexible stylet outward through at least one stylet port and throughintervening tissue to targeted tissues. The stylet guide housing has anoptical viewing means positioned for viewing the stylet which includes afiber optic channel means for receiving a fiber optic viewing device.The fiber optic channel means can include a guide port means fordirecting axial or longitudinal movement of a fiber optic device withrespect to the stylet guide means in a viewing zone.

The device preferably includes a flushing liquid channel in the styletguide housing having an exit port positioned to direct flushing liquidissuing therefrom across the end of a fiber optic device when positionedin the viewing zone.

The optical viewing means can optionally comprise a viewing windowpositioned in the stylet guide housing for viewing the stylet when it isdirected outward from its respective stylet port. The optical viewingmeans can include a fiber optic channel in the stylet guide housing forreceiving the a fiber optic viewing device and aligning the viewing endthereof with the viewing window. Windowed devices can include a flushingliquid channel in the stylet guide housing having an exit portpositioned to direct flushing liquid issuing therefrom across a surfaceof the viewing window.

The device preferably includes at least one flushing liquid return lumenextending to the stylet guide housing.

In the preferred embodiment of this invention, the stylet comprises anelectrical conductor enclosed within a non-conductive sleeve, theelectrical conductor being a radiofrequency electrode.

In one embodiment, the stylet guide housing has a tip portion in whichthe stylet guide means is positioned and the fiber optic channel meansterminates at a position behind the tip, whereby surfaces adjacent thetip portion can be viewed. This can include a transverse depressionpositioned between said position behind the tip and the tip which opensthe viewing field of a fiber optic when positioned in the fiber opticchannel. In some embodiments, the tip defines an fiber optic passagewaymeans for axial or longitudinal extension of the fiber optic to the endof the style guide housing. The passageway means can be a longitudinalhole extending to the end of the housing. Alternatively, the fiber opticpassageway means is an axial or longitudinal depression extending to theterminal surface of the tip and the transverse depression, to open theaxial viewing field of a fiber optic when positioned in the fiber opticchannel.

Alternatively, the stylet guide housing can include a window extendingto said tip for the viewing field of a fiber optic when positioned inthe fiber optic channel.

The invention includes the medical probe device in combination with afiber optic viewing assembly comprising an eyepiece, a fiber optic, afocal lens, and means for adjusting the axial or longitudinal positionof the focal lens with respect to the fiber optic.

Some embodiments include a stylet positioned in at least one of saidstylet guide means, the stylet axis forming an angle of from 10° to 90°with the central axis of the stylet guide housing. In one configuration,the stylet guide housing has an open end with a curved lip whichmaintains the stylet axis at said angle.

The device can have a system to maintain precise positioning of thestylet tip comprising a catheter having a stylet guide housing at itsdistal end and a tension and torque tube assembly at the proximal endthereof. The stylet guide housing has at least one stylet port in a sidethereof and stylet guide means for directing a flexible stylet outwardthrough a stylet port and through intervening tissue to targetedtissues. The tension and torque assembly can include a twist controlknob and torque coupler, an outer torque tube attached to the torquecoupler and extending from the torque coupler through the twist controlknob to the stylet guide housing. The tension and torque tube assemblyincludes an adjusting block means, an non-extendable tension tube havingits proximal end secured to the adjusting block and its distal endsecured to the stylet guide housing, the non-extendable tension tubebeing enclosed within the torque tube and enclosing at least one stylet.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an RF ablation catheter embodiment ofthis invention with an fiber optic viewing accessory.

FIG. 2 is a cross-sectional view of the optics connecting assembly ofthe embodiment of FIG. 1.

FIG. 3 is an exploded, isometric view of the optics connecting assemblyof the embodiment of FIG. 1.

FIG. 4 is an enlarged cross-sectional view of the fiber optic extensionsystem of the embodiment shown in FIGS. 1-3.

FIG. 5 is a cross-sectional view of the optics system of the embodimentshown in FIG. 1.

FIG. 6 is a cross-sectional view of the fiber optic viewing accessoryshown in FIG. 1 with the fiber optic viewer retracted.

FIG. 7 is a cross-sectional view of the fiber optic viewing accessoryshown in FIG. 1 with the fiber optic viewer extended.

FIG. 8 is a fragmented cross-sectional view of a preferred catheter tipand stylet guide housing of this invention.

FIG. 9 a distal end view of the catheter tip and style guide housingshown in FIG. 8.

FIG. 10 is a proximal end view of the unassembled catheter tip andstylet guide housing shown in FIG. 8, showing the lumina for thecomponents thereof.

FIG. 11 is a cross-sectional view of an alternative catheter tip andstylet guide housing embodiment with a fiber optic viewing windowpermitting a view of the stylet deployment.

FIG. 12 is a isometric view of a further alternative catheter tip andstylet guide housing embodiment with a fiber optic viewing window in theend thereof.

FIG. 13 is a isometric view of a still further alternative catheter tipand stylet guide housing embodiment with two fiber optic viewingwindows, one at the end of the housing and the other rearward of thestylets.

FIG. 14 is cross-sectional side view of an alternative 90° stylet guidehousing shown in FIG. 8 with the stylet omitted.

FIG. 15 is a cross-sectional side view of an alternative 45° styletguide housing of this invention.

FIG. 16 is a cross-sectional side view of an alternative 30° styletguide housing of this invention.

FIG. 17 is a cross-sectional side view of an alternative 10° styletguide housing of this invention.

FIG. 18 is a schematic view of a stylet deployment into a portion of aprostate protruding into the urinary bladder.

FIG. 19 is a side view of a 45° shovel nose stylet guide of thisinvention.

FIG. 20 is a side view of a 30° shovel nose stylet guide of thisinvention.

FIG. 21 is a side view of a 10° shovel nose stylet guide of thisinvention.

FIG. 22 is an end view of a shovel nose stylet guide of FIG. 19 for asingle stylet.

FIG. 23 is an end view of a shovel nose stylet guide of FIG. 19 for twostylets.

FIG. 24 is an exploded view of the RF ablation catheter shown in FIG. 1.

FIG. 25 is an isometric view of the adjuster block and tension tubeassembly of the RF ablation catheter shown in FIG. 24.

FIG. 26 is a detailed view "A" of the tension tube connections shown inFIG. 25.

FIG. 27 is an exploded view of the sleeve and electrode slide blockassembly of the embodiment shown in FIG. 24.

FIG. 28 is a schematic view of a deployment of two stylets in a prostateshowing a stylet orientation for overlapping ablation zone method.

DETAILED DESCRIPTION OF THE INVENTION

The device of this invention provides a precise controlled positioningof a treatment stylet in a tissue targeted for treatment, ablation orsampling from a catheter positioned in the vicinity of targeted tissues.

The term "stylet" as used hereinafter is defined to include both solidand hollow probes which are adapted to be passed from a catheter portthrough normal tissue to targeted tissues. The stylet is shaped tofacilitate easy passage through tissue. It can be a solid wire, thinrod, or other solid shape or it can be a thin hollow tube or other shapehaving a longitudinal lumen for introducing fluids to or removingmaterials from a site. The stylet can also be a thin hollow tube orother hollow shape, the hollow lumen thereof containing a reinforcing orfunctional rod or tube such as a laser fiber optic. The styletpreferably has a sharpened end to reduce resistance and trauma when itis pushed through tissue to a target site.

The stylet can be designed to provide a variety of medically desiredtreatments of a selected tissue. As a radiofrequency electrode ormicrowave antenna, it can be used to ablate or destroy targeted tissues.As a hollow tube, it can be used to deliver a treatment fluid such as aliquid to targeted tissues. The liquid can be a simple solution or asuspension of solids, for example, colloidal particles, in a liquid.Since the stylet is very thin, it can be directed from the catheterthrough intervening normal tissue with a minimum of trauma to the normaltissue.

The device and method of this invention provide a more precise,controlled medical treatment which is suitable for destroying cells ofmedically targeted tissues throughout the body, both within and externalto body organs. The device and method are particularly useful fortreating benign prostate hyperplasia (BPH), and the device and its useare hereinafter described with respect to BPH, for purposes ofsimplifying the description thereof. It will be readily apparent to aperson skilled in the art that the device and method can be used todestroy body tissues in any body cavities or tissue locations that areaccessible by percutaneous or endoscopic catheters, and is not limitedto the prostate. Application of the device and method in all of theseorgans and tissues are intended to be included within the scope of thisinvention.

BPH is a condition which arises from the benign replication and growthof cells in the prostate, forming glandular and stromal nodules whichexpand the prostate and constrict the opening of the prostatic urethra.Glandular nodules are primarily concentrated within the transition zone,and stromal nodules within the periurethral region. Traditionaltreatments of this condition have included surgical removal of theentire prostate gland, digital removal of the adenoma, as well astransurethral resection of the urethral canal and prostate to removetissue and widen the passageway. One significant and seriouscomplication associated with these procedures is iatrogenic sterility.More recently, laser treatment has been employed to remove tissue,limiting bleeding and loss of body fluids. Balloons have also beenexpanded within the urethra to enlarge its diameter, with and withoutheat, but have been found to have significant limitations.

Microwave therapy has been utilized with some success by positioning amicrowave antenna within the prostatic urethra and generating heat inthe tissue surrounding the urethra with a microwave field. Coolants aresometimes applied within the catheter shaft to reduce the temperature ofthe urethral wall. This necessitates complicated mechanisms to provideboth cooling of the immediately adjacent tissues while generating heatin the more distant prostatic tissue. This technique is similar tomicrowave hyperthermia. Similarly, radiofrequency tissue ablation withelectrodes positioned within the urethra exposes the urethral wall todestructive temperatures. To avoid this, temperature settings requiredto protect the urethra must be so low that the treatment time requiredto produce any useful effect is unduly extended, e.g. up to three hoursof energy application.

One embodiment of the device of this invention uses the urethra toaccess the prostate and positions RF electrode stylets directly into thetissues or nodules to be destroyed. The portion of the stylet conductorextending from the urethra to targeted tissues is enclosed within alongitudinally adjustable sleeve shield which prevents exposure of thetissue adjacent to the sleeve to the RF current. The sleeve movement isalso used to control the amount of energy per unit surface area which isdelivered by controlling the amount of electrode exposed. Thus theablation is confined to the tissues targeted for ablation, namely thosecausing the mechanical constriction. Other aspects of the invention willbecome apparent from the drawings and accompanying descriptions of thedevice and method of this invention. It will be readily apparent to aperson skilled in the art that this procedure can be used in many areasof the body for percutaneous approaches and approaches through bodyorifices.

FIG. 1 is an isometric view of an RF ablation catheter embodiment ofthis invention with a fiber optic viewing accessory. The flexiblecatheter 2, attached to handle 4, has a terminal stylet guide 6 with twostylets 8. The handle has stylet electrode tabs 10 and 11 and sleevetabs 12 and 13 as will be described in greater detail hereinafter. Thehandle 4 is also connected to an optical viewing assembly 14 and RFpower connector 16, transponder connector 18 and thermocouple connectors20. The portions of the catheter 2 leading from the handle 4 to thestylet guide tip 6 can optionally have a graduated stiffness. Forexample, the catheter can be designed to be more stiff near the handleand more flexible near the tip, or any other stiffness profiles. Thecatheter can be constructed of an inner slotted stainless steel tubewith outer flexible sleeve such as is described in U.S. Pat. No.5,322,064, the entire contents of which are incorporated herein byreference. It can also be made of coiled or braided wire to which anouter sleeve is bonded.

The fiber optic viewing assembly in this embodiment includes a lensfocusing assembly 22, a lens viewing assembly support connector 24assembly attached to a male quick disconnect connector 26 by flexibletubing 28.

FIG. 2 is a cross-sectional view and FIG. 3 is an exploded, isometricview of the optics connecting assembly of the embodiment of FIG. 1. Thelens connector assembly 24 comprises receptor housing 30 having athreaded bore 32. Engagement of the threaded bore 32 with the threadedtubular housing connector 34 secures the optical assembly to the handle4 (FIG. 1). An interior cavity 36 of the receptor housing 30 receivesthe distal end of the fiber optic control housing 38, and the opposedsurfaces thereof are sealed by O-ring 40 and flange 42 to prevent escapeof flushing fluid. One end of the flexible tubing 28 engages cylindricalreceptor 44 of the fiber optic control housing 38, and the other endengages a cylindrical receptor 46 in the male quick release member 26.

FIG. 4 is an enlarged cross-sectional view of the fiber optic extensionsystem of the embodiment shown in FIGS. 1-3. Axial or longitudinaladjustment of the fiber optic control housing 38 effects axial orlongitudinal movement of the fiber optic in the stylet guide housing aswill be described in greater detail hereinafter. This axial orlongitudinal adjustment is effected by the relative movement betweeninner surface 48 of housing 30 and the outer surface 50 of the distalend of the fiber optic control housing 38. Advancing movement of thefiber optic control housing 38 (leftward movement in this figure) islimited by the abutment of surface 52 of flange 42 with the opposing endsurface of the receptor housing 30. The flange 42 has an annular distalsleeve terminus 54 which is held between respective cylindrical innersurface 56 of the receptor housing 30 and outer surface 58 of controlhousing 38. Its advancing movement is limited by abutment of surface 60of the flange 42 and opposed abutment surface 62 of the control housing38. Retracting movement of control housing 38 and the fiber opticattached thereto is limited by impingement of annular stop rim 59against O-ring 40.

Flushing liquid to clean the viewing tip of the fiber optic is providedthrough flushing liquid supply bore 64 from a flushing liquid supplyconnector (not shown) and enters the cavity 66. Escape of the liquidfrom between the receptor housing 30 and the control housing 38 isprevented by the sealing engagement of the O-ring 40 with the surfacesopposed thereto and a seal (not shown) in opening 41. The liquid flowsthrough channel 72 and opening 74, and then through a tubing (not shown)surrounding the fiber optic. Outlet port 70 receives a conventionalfiber optic illumination light source connection.

The distal tip of the housing connector has an expanded diameter orflange 78 for connection with the handle 4. The receptor housing has amounting surface 80 at a sloped angle with the axis thereof for engagingan opposed upper surface of handle 4 (FIG. 1).

FIG. 5 is a cross-sectional view of the optics system of the embodimentshown in FIG. 1. The conventional focusing system 22 comprises aneyepiece 82 connected to the end of cylinder 83. Transparent window 84is mounted in the proximal end. A quick disconnect junction 86 ispositioned at the distal end of the cylinder 83. The proximal viewingend of the fiber optic (not shown) is mounted in the cavity 85.

The lens focusing system comprises a conventional convex lens 88 mountedin a lens support cylinder 90. A manual adjusting sleeve 96 is mountedfor sliding movement about the cylinder 83. The adjusting sleeve 96 isattached to the lens support 90 by pin 94 which extends through slot 92.Slot 92 has the shape of a short portion of a helix so that rotation ofsleeve 96 about the sleeve in the clockwise direction andcounter-clockwise moves the lens toward or away from the fiber opticviewing end, respectively, to bring the image into focus for the viewer.

FIG. 6 is a cross-sectional view of the fiber optic viewing accessoryshown in FIG. 1 with the fiber optic viewer retracted, and FIG. 7 is across-sectional view of the fiber optic viewing accessory shown in FIG.2 with the fiber optic viewer extended. As the fiber optic controlhousing 38 is advanced by the operator into the receptor housing 30, theviewing tip 102 of fiber optic 104 is advanced outward through thestylet guide housing 6 toward the tip thereof from the position shown inFIG. 6 to the position shown in FIG. 7, enabling the operator to viewthe duct surfaces surrounding the housing 6 to determine the conditionof these surfaces and locate the position of ducts such as the seminalducts which are to be avoided in the treatment. The stylet housing tip 6is moved to position it in the desired location by movement of thehandle 4 and catheter 2 (FIG. 1). By retracting the fiber optic controlhousing 38 from the housing 30, the fiber optic viewing tip 102 iswithdrawn to the surface of the stylet guide housing 6 as shown in FIG.6 for viewing the surface through which the stylets 8 (FIG. 1) are to beextended.

FIG. 8 is a fragmented cross-sectional view of a preferred catheter tipand stylet guide housing of this invention. The solid catheter tip 106has a lateral depression or saddle 108 therein having a central axisapproximately perpendicular to a plane through the central axis of thetip. The depression 108 has a proximal wall 110. The depression 108 canextend up to approximately half of the thickness of the housing, but atleast sufficiently to unblock the viewing surface of the viewing tip 112of the fiber optic 114. The fiber optic viewing tip 112, when positionedat the opening in wall 110, provides a field of view with lateralmargins 116 and a terminal margin 118. This includes the path of styletsextended outward through ports 120.

FIG. 9 is a distal end view of the catheter tip and style guide housingshown in FIG. 8. The proximal end of depression 108 is split to form twoprojections or ears 122 and 124 which define a longitudinal or axial orlongitudinal groove or saddle 126 extending from the depression 108 tothe terminal tip 128 of the catheter 106. Groove 126 opens the field ofview for the viewing tip 112 when in the solid line position shown inFIG. 8 and permits extension of the fiber optic and its tip (asdescribed with respect to FIGS. 4, 6 and 7) through the longitudinalgroove to the dotted line positions 114' and 112'. In the latterposition, the field of vision has side margins 130 and a terminal margin132. This permits the operator to examine the inner duct surfaces aheadof the catheter tip. In an alternative embodiment, the grove 126 can bereplaced with a hole in the end of the tip having a size and position topermit extension of the fiber optic 114 therethrough.

The fiber optic 114 is positioned in a passageway 134 which issufficiently larger than the fiber optic to permit flow of flushingliquid around the fiber optic to the exit in wall 110. The flushingliquid flow clears debris from the viewing tip. The inner walls of theduct (not shown) surrounding the catheter tip 106 during use confine theliquid flow, so the liquid continues to pass over the fiber optic tipeven when it has been advanced to the dotted line position. Returnflushing liquid lumina 136 and 138 extend through wall 110 for constantremoval of contaminated flushing liquid.

FIG. 10 is a proximal end view of the unassembled catheter tip andstylet guide housing shown in FIG. 8, showing the lumina for thecomponents thereof. The stylets are advanced and retracted throughstylet lumina 140 and 142 to the stylet ports 120. The fiber optic isadvanced and retracted through fiber optic lumen 134. The contaminatedflushing fluid is removed through flushing fluid return lumina 136 and138. Temperature sensor lumen 144 is used to house leads of atemperature sensor (not shown).

FIG. 11 is a cross-sectional view of a catheter tip and stylet guidehousing embodiment with a cylindrical fiber optic viewing windowpermitting a view of the stylet deployment. In this view, the catheterend 146 includes a short cylindrical, transparent window 148 and tip cap150. Stylet guide tubing 152 extends through the enclosure defined bythe window 148 to ports (not shown). The catheter end 146 has a lumen154 in which a fiber optic 155 can be positioned and a transparent plate156 for sealing the end of the lumen 154. The margins 158 of the viewthrough the plate 156 provide a wide 360° view of the inside surface ofa surrounding duct and the extended stylets.

FIG. 12 is an isometric view of a catheter tip and stylet guide housingembodiment with a fiber optic viewing window in the end thereof. Thisstylized view shows a catheter tip 160 with an optic viewing window 162in the tip thereof. It has stylets extending through outlet portstherein, each stylet comprising an antenna 164 surrounded by aninsulating sleeve 166. Temperature sensors 168 and 170 monitor thetemperature in the duct wall surrounding the catheter. In thisembodiment, the inside wall of the duct can be examined as the catheteris advanced to the desired position.

FIG. 13 is a isometric view of a catheter tip and stylet guide housingembodiment with two fiber optic viewing windows, one at the end of thehousing and the other rearward of the stylets. This stylized view showsa catheter tip 172 with two optic viewing windows 174 and 176 therein,and stylets extended through outlet ports therein, each styletcomprising an antenna 178 surrounded by an insulating sleeve 180. Atemperature sensor 182 monitors the temperature in the duct wallsurrounding the catheter. In this embodiment, two windows are provided,accommodating two fiber optics or two positions for a single fiberoptic. Window 174 provides a view of the surrounding as the catheter isadvanced to the desired position. Window 176 provides a view of the ductwall in the vicinity of the stylets.

FIG. 14 is a cross-sectional side view of an alternative 90° styletguide housing shown in FIG. 8 with the stylet omitted. The solidcatheter tip 106 has a curved guide channel 119 leading to port 120through which the stylet is to be guided. Terminal portion 121 of thechannel 119 has an orientation of 90° to the central axis of thehousing.

FIG. 15 is a cross-sectional side view of an alternative 45° styletguide housing of this invention. In this embodiment, the solid cathetertip 184 with lateral depression 186 has a curved channel 188, theterminal portion 190 thereof having an axis which forms an angle "a"with the central axis of the catheter tip. This deploys the antenna 192and insulating sleeve 194 at an angle "a" in a plane through the centralaxis of the catheter tip. In this embodiment, angle "a" is preferablyabout 45°.

FIG. 16 is a cross-sectional side view of an alternative 30° styletguide housing of this invention. In this embodiment, the solid cathetertip 196 with lateral depression 198 has a curved channel 200, theterminal portion 202 thereof having an axis which forms an angle "b"with the central axis of the catheter tip. This deploys the antenna 204and insulating sleeve 206 at an angle "b" in a plane through the centralaxis of the catheter tip. In this embodiment, angle "b" is preferablyabout 30°.

FIG. 17 is a cross-sectional side view of an alternative 10° styletguide housing of this invention. In this embodiment, the solid cathetertip 208 with lateral depression 210 has a curved channel 212, theterminal portion 214 thereof having an axis which forms an angle "c"with the central axis of the catheter tip. This deploys the antenna 216and insulating sleeve 218 at an angle "c" in a plane through the centralaxis of the catheter tip. In this embodiment, angle "c" is preferablyabout 10°.

FIG. 18 is a schematic view of a stylet of FIG. 16 shown deployed totreat a portion of a prostate protruding into the urinary bladder. Thesolid catheter tip 196 is positioned at the end of the urethra 220. Cellproliferation in the upper end 222 of the prostate 224 has caused it toprotrude into space normally occupied by the urinary bladder, pushing aportion of the bladder wall 226 into the cavity and forming arestriction 225 beyond the end of the urethra. The stylet sleeve 206 andelectrode 204 are extended at an angle of about 30° through the urethralwall into a portion of the protruded prostate, and RF current is appliedto form the lesion 228. This will reduce the protruded prostate,promoting its retraction from the urethral wall and opening therestriction of the outlet end of the urethra. The catheter having adesired angle can be selected from those having angles "a", "b" or "c"shown in FIGS. 15-17 to precisely orient the stylet and effect precisepenetration of prostate tissue which extends beyond the end of theurethra, for example.

FIG. 19 is a side view of a 45° shovel nose stylet guide of thisinvention. In this embodiment, the catheter tip 230 has the shape of ashovel or scoop, the extended lip 232 of which guides the stylet 234 ina desired angle "d". This configuration opens the upper viewing field236 of the fiber optic 238 in the unextended position and permits anunobstructed viewing field 240 in the fully extended position. In thisembodiment, the angle "d" is about 45°.

FIG. 20 is a side view of a 30° shovel nose stylet guide of thisinvention. In this embodiment, the catheter tip 242 has the shape of ashovel or scoop, the extended lip 244 of which guides the stylet 246 ina desired angle "e". This configuration opens the upper viewing field248 of the fiber optic 250 in the unextended position and permits anunobstructed viewing field 252 in the fully extended position. In thisembodiment, the angle "e" is about 30°.

FIG. 21 is a side view of a 10° shovel nose stylet guide of thisinvention. In this embodiment, the catheter tip 254 has the shape of ashovel or scoop, the extended lip 256 of which guides the stylet 258 ina desired angle "f". This configuration opens the upper viewing field260 of the fiber optic 262 in the unextended position and permits anunobstructed viewing field 264 in the fully extended position. In thisembodiment, the angle "f" is about 10°.

FIG. 22 is an end view of a shovel nose stylet guide of FIG. 19 for asingle stylet 234.

FIG. 23 is an end view of an alternative embodiment of a shovel nosestylet guide for two stylets 266 and 268, the stylet guide tip 270having a shovel lip 272 and fiber optic 274.

FIG. 24 is an exploded view of the RF ablation catheter assembly shownin FIG. 1. The upper handle plate 276 has two central slots 278 and 280through which the electrode control slides 11 are attached to respectiveleft electrode slide block 282 and right electrode slide block 284.Sleeve control slides 12 and 13 are attached through outer slots 286 and288 to respective left sleeve slide block 290 and right sleeve slideblock 292. Fiber optic receptor housing 30 is mounted on the proximalsurface of the upper handle plate 276. The electrical receptor 294 isreceived in respective cavities 296 and 298 in the respective upperhandle plate 276 and lower handle plate 300 attached thereto. The lowerhandle plate 300 has a central cavity 302 which accommodates theelectrode and sleeve slide blocks and associated elements.

Microswitch activator blocks 304 (only left sleeve block shown) areconnected to the sleeve slide blocks 290 and 292. They are positioned toactuate the microswitches 306 when the respective sleeve block (andsleeve attached thereto) have been advanced. The microswitches 306 holdthe respective RF power circuits open until the respective sleeves areadvanced to a position beyond the urethra wall and into the prostate toprevent direct exposure of the urethra to the energized RF electrodes.Extension of the sleeve 5 mm beyond the guide is usually sufficient toprotect the urethra.

The tension-torque tube assembly 308 is mounted in the distal end of thehousing in the receptor 310.

FIG. 25 is an isometric view of the adjuster block and tension tubeassembly 308 of the RF ablation catheter shown in FIG. 24. The torquetube 312 extends from the torque coupler 314 through the twist controlknob 316 to the stylet guide 6. Bending flexure of the torque tube 312during use lengthens the path from the handle to the guide tip 6. Toprevent a resulting retraction of the stylet sleeve and electrodecomponents when the torque tube 312 is flexed, a tension tube 318 havinga fixed length and diameter smaller than the inner diameter of thetorque tube 312 is provided. The distal end of the tension tube 318 issecurely attached to the stylet guide 6, and the proximal end 320 issecured to the adjuster block 322, for example by an adhesive. The axialor longitudinal position of the adjuster block 322 can be adjusted toinsure the stylets are initially positioned just inside the outlet portsin the stylet guide 6. Torque coupler 314 is mounted on the couplerblock 324. Twist control knob stop pin 326 extends into a grove (notshown) and limits rotation of the control knob 316.

FIG. 26 is a detailed view "A" of the distal end tension tubeconnections of the tension tube shown in FIG. 25. The tension tube 318is securely connected to the proximal end 328 of the stylet guide 6, forexample by a length of shrink tubing 330.

FIG. 27 is an exploded view of the sleeve and electrode slide blockassembly of the embodiment shown in FIG. 24. The right sleeve slideblock 292 has a projection 332 which extends inward under the rightelectrode slide block 284. Right sleeve connector 334 is mounted to theinner end of the projection 332, secured to the end of the proximal endof the sleeve 336. Right electrode connector 338 is attached to an innersurface of the electrode slide block 284 and is secured to the proximalend of electrode 340. The right sleeve and electrode slide blocks 292and 284 are slidingly attached to the right friction adjustment rail 342by screws (not shown) through slots 344 and 346, the screws beingadjustable to provide sufficient friction between the blocks and therail 342 to provide secure control over the stylet movement. The leftsleeve slide block 290 and left electrode slide block 282 are mirrorreplicas of the right blocks and are similarly mounted on the leftfriction rail 348. The left sleeve and electrodes are not shown.

FIG. 28 is a schematic view of a deployment of two stylets in a prostateshowing stylet orientation for overlapping ablation zone method of thisinvention. For purposes of illustration but not by way of limitation,the prostate has been selected for this explanation, and application ofthis method and assembly to other areas of the body are intended to beincluded.

The tissues to be treated for the treatment of BPH are located in thetransition zone 428 of the prostate. A catheter of this invention 430has been inserted up the urethra 432 to a position adjacent theprostate. Two stylets 434 and 436 have been passed through the urethrawall 432 through forward movement of tabs 12 and 13 (FIG. 1) and throughsurrounding tissue into targeted tissues. The non-conducting sleeves 438and 440 have been retracted by rearward movement of sleeve tabs 12 and13 to expose a portion of the respective electrical conductors 442 and444 at the end of each stylet. The angle between the axes of the styletsin this embodiment, "f", is less than 180°, preferably less than 110°.For most overlapping ablations, angles of 15° to 90°, and more usuallyfrom 20° to 70° are most practical. A Grounding plate (not shown) isplaced on the body exterior.

When electrodes 442 and 444 are supplied with RF current, the circuitfrom the electrodes to a grounding plate is closed. The current densityflowing through the tissue passes through targeted tissues to betreated, creating lesions having the approximate cross-sectional shapeof overlapping zones 446 and 448. The current density rapidly decreasesas a function of distance, limiting the size of the lesions. In thismanner, lesions can be caused to overlap to form a larger lesion,increasing the efficiency of the treatment. It will be readily apparentthat these processes can be carried out concurrently, as described, orsequentially, and these variations are intended to be included in thisinvention.

Although preferred embodiments of the subject invention have beendescribed in some detail, it is understood that obvious variations canbe made without departing from the spirit and the scope of the inventionas defined by the appended claims.

We claim:
 1. A medical probe device for medical treatment of tissue of aprostate through a urethra defined by a urethral wall comprising a guidehousing having proximal and distal extremities and having a passagewayextending from the proximal extremity to the distal extremity, a styletmounted in the guide housing, means carried by the distal extremity ofthe guide housing and in communication with said passageway fordirecting the stylet sidewise of the guide housing, the stylet includinga flexible radio frequency electrode and an insulating sleeve coaxiallymounted on the electrode, handle means coupled to the proximal extremityof the guide housing for introducing the distal extremity of the guidehousing into the urethra into the vicinity of the prostate, said handlemeans including means secured to the stylet for advancing the styletfrom the passageway of the guide housing to cause the radio frequencyelectrode and the insulating sleeve to penetrate the urethral wall andto extend into the tissue of the prostate with the insulating sleeveextending through the urethral wall and the radio frequency electrodehaving a predetermined length in the tissue of the prostate, means forsupplying radio frequency energy to the radio frequency electrode tocause the temperature of the tissue of the prostate adjacent thepredetermined length of the radio frequency electrode to be raised tocause destruction of cells in the tissue of the prostate and an opticalviewing device positioned in the guide housing having a viewing fieldthat extends forwardly and sidewardly of the guide housing to permitviewing of the radio frequency electrode and the insulating sleeve asthey are deployed sidewise from the distal extremity of the guidehousing.
 2. A medical probe device as in claim 1 wherein the guidehousing includes a channel receiving said optical viewing device andpermitting longitudinal movement of the optical viewing device withrespect to the guide housing to shift the viewing field.
 3. A medicalprobe device as in claim 2 wherein the distal extremity of the guidehousing has a tip and wherein the optical device viewing channelterminates at a position proximal of the tip.
 4. A medical probe deviceas in claim 3 wherein said guide housing is provided with a transversedepression proximal of the tip and within the viewing field of theoptical viewing device.
 5. A medical probe device as in claim 3 whereinthe distal extremity of the guide housing has a tip which includes awindow extending across the viewing field.
 6. A medical probe device asin claim 2 wherein the distal extremity of the guide housing has a tipand wherein the optical viewing device channel extends through the tip.7. A medical probe device as in claim 6 wherein the distal extremity ofthe guide housing is provided with a transverse depression extendingthrough and across the optical device viewing channel.
 8. A medicalprobe device as in claim 1 wherein said guide housing includes aflushing liquid channel for directing a flushing liquid into the viewingfield.
 9. A medical probe device as in claim 8 wherein said guidehousing includes at least one flushing liquid return lumen.
 10. Amedical probe device as in claim 1 wherein the optical viewing devicecomprises an eyepiece, a fiber optic, a focal lens and means foradjusting the longitudinal position of the focal lens with respect tothe fiber optic.
 11. A medical probe device for medical treatment oftissue of a prostate through a urethra defined by a urethral wallcomprising a guide housing having proximal and distal extremities andhaving a passageway extending from the proximal extremity to the distalextremity, a stylet mounted in the guide housing, means carried by thedistal extremity of the guide housing and in communication with saidpassageway for directing the stylet sidewise of the guide housing, thestylet including a flexible radio frequency electrode and a layer ofinsulating material coaxially mounted on the electrode, handle meanscoupled to the proximal extremity of the guide housing for introducingthe distal extremity of the guide housing into the urethra into thevicinity of the prostate, said handle means including means secured tothe stylet for advancing the stylet from the passageway of the guidehousing to cause the radio frequency electrode and the layer ofinsulating material to penetrate the urethral wall and to extend intothe tissue of the prostate with the layer of insulating materialextending through the urethral wall and the radio frequency electrodehaving a length in the tissue of the prostate, means for supplying radiofrequency energy to the radio frequency electrode to cause thetemperature of the tissue of the prostate adjacent the length of theradio frequency electrode to be raised to cause destruction of cells inthe tissue of the prostate and an optical viewing device positioned inthe guide housing having a viewing field that extends forwardly andsidewardly of the guide housing to permit viewing of the radio frequencyelectrode and the layer of insulating material as they are deployedsidewise from the distal extremity of the guide housing.
 12. A medicalprobe device as in claim 11 wherein the distal extremity of the guidehousing has a tip and wherein the optical viewing device terminates at aposition proximal of the tip.
 13. A medical probe device as in claim 12wherein the distal extremity of the guide housing is provided with atransverse depression proximal of the tip and within the viewing fieldof the optical viewing device.
 14. A medical probe device as in claim 11wherein the distal extremity of the guide housing has a tip whichincludes a window extending across the viewing field.
 15. A medicalprobe device as in claim 11 wherein at least a portion of the distalextremity of the guide housing is transparent to permit the opticalviewing device to view the radio frequency electrode and the layer ofinsulating material through the distal extremity of the guide housing asthey are deployed sidewise from the distal extremity of the guidehousing.
 16. A medical probe device for medical treatment of tissue of aprostate through a urethra defined by a urethral wall comprising a guidehousing having proximal and distal extremities and having a passagewayextending from the proximal extremity to the distal extremity, aflexible radio frequency electrode mounted in the guide housing, meanscarried by the distal extremity of the guide housing and incommunication with said passageway for directing the radio frequencyelectrode sidewise of the guide housing, handle means coupled to theproximal extremity of the guide housing for introducing the distalextremity of the guide housing into the urethra into the vicinity of theprostate, said handle means including means secured to the radiofrequency electrode for advancing the radio frequency electrode from thepassageway of the guide housing to cause the radio frequency electrodeto penetrate the urethral wall and to extend into the tissue of theprostate, means for supplying radio frequency energy to the radiofrequency electrode to cause the temperature of the tissue of theprostate adjacent the radio frequency electrode to be raised to causedestruction of cells in the tissue of the prostate and an opticalviewing device positioned in the guide housing having a viewing fieldthat extends forwardly and sidewardly of the guide housing to permitviewing of the radio frequency electrode as it is deployed sidewise fromthe distal extremity of the guide housing.
 17. A medical probe device asin claim 16 together with a layer of insulating material coaxiallymounted about at least a portion of the radio frequency electrode.
 18. Amedical probe device as in claim 16 wherein the radio frequencyelectrode is provided with a longitudinal lumen extending therethrough.19. A medical probe device for use in a human body comprising anelongate member having proximal and distal extremities and having apassageway therein extending along a longitudinal axis from the proximalextremity to the distal extremity, an elongate needle mounted in thepassageway and having proximal and distal extremities, handle meanscoupled to the proximal extremity of the elongate member for introducingthe distal extremity of the elongate member into the body, meansconnected to the elongate needle for causing advancement of the elongateneedle through the passageway, the distal extremity of the elongatemember being in communication with the passageway and permitting thedistal extremity of the elongate needle to be advanced out of thepassageway sideways at an angle with respect to the longitudinal axis,an optical viewing device having a distal extremity with a field of viewand means carried by the proximal extremity of the elongate member formounting the distal extremity of the optical viewing device within thedistal extremity of the elongate member and for moving the distalextremity of the optical viewing device relative to the elongate memberfrom a first longitudinal position to permit viewing forward of theelongate member for guiding the distal extremity of the elongate memberwithin the body to a second longitudinal position proximal of the firstlongitudinal position to permit viewing the distal extremity of theelongate needle as it is advanced from the passageway sideways of thelongitudinal axis.
 20. A device as in claim 19 wherein the passagewayextends to a port at the distal extremity of the elongate member andwherein the first longitudinal position is distal of the port and thesecond longitudinal position is proximal of the port.
 21. A device as inclaim 20 wherein the distal extremity of the elongate member has arounded tip and a transversely extending recess proximal of the roundedtip, the port disposed between the rounded tip and the recess.
 22. Adevice as in claim 19 wherein the elongate needle is a needle electrode,an insulating sleeve coaxially mounted on the needle electrode.
 23. Adevice as in claim 22 together with means mounted on the proximalextremity of the elongate member and connected to the handle means andto the insulating sleeve for causing the insulating sleeve to moverelative to the needle electrode.
 24. A medical probe device comprisingan elongate guide housing having proximal and distal extremities andhaving a passageway therein extending from the proximal extremity to thedistal extremity along a longitudinal axis, a stylet mounted in theguide housing and having proximal and distal extremities, handle meanscoupled to the proximal extremity of the guide housing, the handle meansincluding means connected to the stylet for causing advancement of thestylet through the passageway, the distal extremity of the guide housingbeing in communication with the passageway and permitting the distalextremity of the stylet to be advanced out of the passageway sidewise atan angle with respect to the longitudinal axis and an optical viewingdevice mounted in the guide housing and having a distal extremitypositioned in the distal extremity of the guide housing and having afield of view which permits viewing the distal extremity of the styletas it is advanced from the passageway sidewise of the longitudinal axis.25. A device as in claim 24 wherein the stylet includes a conductiveradio frequency electrode and an insulating sleeve coaxially mounted onthe conductive radio frequency electrode and exposing a length of theconductive radio frequency electrode.
 26. A device as in claim 24 foruse in a human body together with means carried by the proximalextremity of the guide housing for mounting the distal extremity of theoptical viewing device within the distal extremity of the guide housingand for moving the distal extremity of the optical viewing devicerelative to the guide housing from a first longitudinal position topermit viewing forward of the guide housing for guiding the distalextremity of the guide housing within the body to a second longitudinalposition proximal of the first longitudinal position to permit viewingthe distal extremity of the stylet as it is advanced from the passagewaysidewise of the longitudinal axis.
 27. A medical probe device formedical treatment of tissue of a prostate in a human body through aurethra defined by a urethral wall comprising an elongate member havingproximal and distal extremities and having a passageway thereinextending along a longitudinal axis from the proximal extremity to thedistal extremity, a stylet mounted in the passageway and having proximaland distal extremities, the stylet including a flexible radio frequencyelectrode and a layer of insulating material coaxially mounted on theradio frequency electrode, handle means coupled to the proximalextremity of the elongate member for introducing the distal extremity ofthe elongate member into the body, the handle means including meansconnected to the stylet for causing advancement of the stylet throughthe passageway, the distal extremity of the elongate member having meansfor directing the distal extremity of the stylet out of the passagewaysideways at an angle with respect to the longitudinal axis, an opticalviewing device having a distal extremity with a field of view and meanscarried by the proximal extremity of the elongate member for mountingthe distal extremity of the optical viewing device within the distalextremity of the elongate member and for moving the distal extremity ofthe optical viewing device relative to the elongate member from a firstlongitudinal position to permit viewing forward of the elongate memberfor guiding the distal extremity of the elongate member within the bodyto a second longitudinal position proximal of the first longitudinalposition to permit viewing the distal extremity of the stylet as it isadvanced from the passageway sideways of the longitudinal axis into thetissue of the prostate.
 28. A medical probe device as in claim 27wherein at least a portion of the distal extremity of the elongatemember is transparent to permit the optical viewing device to view thedistal extremity of the stylet through the distal extremity of theelongate member as it is advanced from the passageway sideways of thelongitudinal axis into the tissue of the prostate.
 29. A medical probedevice for medical treatment of tissue of a prostate through a urethradefined by a urethral wall comprising a guide housing having proximaland distal extremities and having a passageway extending from theproximal extremity to the distal extremity, a stylet for deliveringradio frequency energy into the tissue of the prostate mounted in theguide housing, means carried by the distal extremity of the guidehousing and in communication with said passageway for directing thestylet sidewise of the guide housing, handle means coupled to theproximal extremity of the guide housing for introducing the distalextremity of the guide housing into the urethra into the vicinity of theprostate, said handle means including means secured to the stylet foradvancing the stylet from the passageway of the guide housing to causethe stylet to penetrate the urethral wall and to extend into the tissueof the prostate, means for supplying radio frequency energy to thestylet to cause the temperature of the tissue of the prostate adjacentthe stylet to be raised to cause destruction of cells in the tissue ofthe prostate and an optical viewing device positioned in the guidehousing having a viewing field that extends forwardly and sidewardly ofthe guide housing to permit viewing of the stylet as it is deployedsidewise from the distal extremity of the guide housing.
 30. A medicalprobe device for medical treatment of tissue of a prostate through aurethra defined by a urethral wall comprising a guide housing havingproximal and distal extremities and having a passageway extending fromthe proximal extremity to the distal extremity, a stylet mounted in theguide housing, means carried by the distal extremity of the guidehousing and in communication with said passageway for directing thestylet sidewise of the guide housing, the stylet including a flexibleradio frequency electrode and a layer of insulating material coaxiallymounted on the electrode, handle means coupled to the proximal extremityof the guide housing for introducing the distal extremity of the guidehousing into the urethra into the vicinity of the prostate, said handlemeans including means secured to the stylet for advancing the styletfrom the passageway of the guide housing to cause the radio frequencyelectrode and the layer of insulating material to penetrate the urethralwall and to extend into the tissue of the prostate with the layer ofinsulating material extending through the urethral wall and the radiofrequency electrode having a length in the tissue of the prostate forcausing the temperature of the tissue of the prostate adjacent thelength of the radio frequency electrode to be raised and thus destroycells in the tissue of the prostate and an optical viewing devicepositioned in the guide housing having a viewing field that extendsforwardly and sidewardly of the guide housing, at least a portion of thedistal extremity of the guide housing being transparent to permit theoptical viewing device to view the radio frequency electrode and thelayer of insulating material through the distal extremity of the guidehousing as they are deployed sidewise from the distal extremity of theguide housing.